Most computer user interfaces allow a user to provide input using a keyboard as well as a secondary input device, such as a mouse or trackball. The secondary input device is typically used for moving a cursor or pointer on a display screen, and providing input in the form of selection of elements displayed on the display screen at the location of the cursor/pointer. Many secondary input devices have multiple inputs, e.g., multiple buttons, scroll wheels, fingerprint scanner, and the like. A user's interaction with elements on the display screen may be affected based on which of the multiple inputs the user actuates.
In addition, some computer systems differentiate between single-clicking and double-clicking display elements, and perform different actions as a result. For example, many computer systems highlight an item when a user single-clicks on an item displayed on the display screen, and launch an item when the user double-clicks the item displayed on the display screen. The same computer systems may also navigate menus based on single-click selections of menu elements, but require double clicking when selecting elements in other areas of the user interface. In addition, in order for a double-click event to be effective, the user must double-click the input device within a certain amount of time, which is often difficult for some users (e.g., elderly or handicapped individuals).
The above problems result in users being confused by computer user interfaces, making it difficult for all users to succeed at building lists of items in an effective user interface, and having problems manipulating the user interface to accomplish the user's goal, i.e., build a list of a desired set of elements. Another problem that affects the user experience is that users are not able to see the list as it is being built and being easily able to modify the list (e.g., by adding or removing items). Another problem is that the actual user interface mechanism is difficult for users to manipulate physically, e.g., by having to select a small checkbox, drag and drop items directly, or other secondary mechanisms.
Thus, it would be an advancement in the art to provide a more simplistic user interface through which a user could build a list of a desired set of items with less difficulty and complexity than previously provided.